Methods for Binding Particulate Solids

ABSTRACT

Provided are methods for binding particulate solids in a polymer fiber matrix utilizing composite waste products. A mixture of composite waste products and particulate solids is formed into solid products to create degradation resistant solid units which capture the particulate solids.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.11/013,948, filed on Dec. 16, 2004, and entitled “METHOD FOR BINDINGPARTICULATE SOLIDS,” which in turn claims priority from U.S. ProvisionalApplication No. 60/530,728, filed on Dec. 17, 2003, and entitled,“METHOD FOR BINDING PARTICULATE SOLIDS.” Both applications are entirelyincorporated herein by reference.

TECHNICAL FIELD

The present disclosure is generally related to solid form productionand, more particularly, is related to methods for binding particulatesolids.

BACKGROUND

In the past, particulate materials, such as coal fines, coke breeze, sawdust, and other biomass wastes, have presented storage, handling, andprocessing challenges. Additionally, metal oxides from blast furnaces,basic oxygen furnaces and electric arc furnaces have routinely beendiscarded, in large quantities, creating a source of pollution andpresenting an environmental hazard, which continues for decades.Further, composite waste products, including post-consumer andpost-industrial carpet waste, are routinely discarded into waste storagefacilities, such as landfills. In addition to presenting challengesrelated to handling the composite waste products, the slow rate ofdecomposition results in an unfavorable environmental impact thatcontinues for decades.

Prior attempts at disposing of coke breeze, coal fines, and otherparticulate solids by producing solid forms, such as briquettes orpellets, have been largely unsuccessful because the particulate solidsdo not adequately bind and the resulting product can be mechanicallyunstable, disintegrating or degrading back into small, fine particlesduring storage and handling. Other attempts at producing solid formsfrom the particulate solids may use costly binder materials, such aspetroleum pitch or water-based latexes, and may use costly and complexprocessing techniques. Water-based materials will reduce the heatingvalue of fuel based solids and produce a formed material which isunstable during outside storage and transport and may disintegratecausing fugitive dust emissions or ground water contamination. Further,previous attempts have utilized binders, including petroleum-basedmaterials, which become tacky and difficult to transport at ambient andelevated temperatures, and may cause contamination and run-off problemswhen stored outside.

Thus, a heretofore-unaddressed need exists in the industry to addressthe aforementioned deficiencies and inadequacies.

SUMMARY

Briefly described, an embodiment of the present disclosure can be viewedas a method for binding particulate solids, comprising: reducing acomposite waste product; adding particulate solids to the compositewaste product; blending the particulate solids with the composite wasteproduct, wherein the particulate solids and the composite waste productconstitute a consistent mixture; adding energy to the mixture toincrease a process temperature, such that a component of the compositewaste product changes from a solid state to a fluid state; and formingthe mixture into solid formed products.

Another embodiment of the present disclosure can also be viewed as amethod for capturing particulate solids in a degradation resistant form,comprising: a reducing means for shredding or pelletizing carpet; asupplying means for adding particulate solids to the carpet; a mixingmeans for blending the carpet and the particulate solids into a mixture;a heating means for elevating the temperature of the mixture such that abinder element of the carpet achieves a liquid state and a fiber elementof the carpet retains a solid state; and a forming means for convertingthe mixture into a formed solid, wherein the formed solid comprises apolymer fiber matrix which captures the particulate solids.

Another embodiment of the present disclosure can be viewed as adegradation resistant fiber matrix solid product comprising: a compositewaste product including a binder element and a fiber element, whereinthe binder element fluidizes at a first temperature, wherein the fiberelement fluidizes at a second temperature, and wherein the firsttemperature is lower than the second temperature; and a particulatesolid product, wherein the binder captures the particulate solid productwhen blended at a temperature in the range between the first temperatureand the second temperature.

Other methods, objects, and features of the present disclosure will beor become apparent to one with skill in the art upon examination of thefollowing drawings and detailed description. It is intended that allsuch additional systems, methods, features, and advantages be includedwithin this description, be within the scope of the present disclosure,and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with referenceto the following drawings. The components in the drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the present disclosure. Moreover, in thedrawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is a block diagram illustrating an embodiment of the methodsdisclosed herein.

FIG. 2 is a block diagram illustrating an exemplary process under themethods disclosed herein.

FIG. 3 is a block diagram illustrating an exemplary process under themethods disclosed herein.

FIG. 4 is a block diagram illustrating a non-limiting example ofelements in a composite waste product.

FIG. 5 is a block diagram illustrating an exemplary process under themethods disclosed herein.

FIG. 6 is a block diagram illustrating an exemplary process under themethods disclosed herein.

FIG. 7 is a block diagram illustrating components of an exemplaryproduction plant for practicing the methods disclosed herein.

DETAILED DESCRIPTION

Reference is now made in detail to the description of the embodiments asillustrated in the drawings. While several embodiments are described inconnection with these drawings, there is no intent to limit thedisclosure to an embodiment or embodiments disclosed herein. On thecontrary, the intent is to cover all alternatives, modifications, andequivalents.

Reference is made to FIG. 1, which is a block diagram illustrating anembodiment of the methods disclosed herein. The method 100 includesreducing a composite waste product 110 through, for example, a shreddingor pelletizing process. An exemplary composite waste product in anembodiment herein includes waste carpet. Waste carpet can be, forexample, consumer recycled carpet or industrial waste carpet. One ofordinary skill in the art knows or will know that the reducing functioncan be performed as a separate step prior to the other steps of themethod described herein or, alternatively, as an integrated step.

After the composite waste product is reduced, particulate solids areadded to the composite waste product 120. The particulate solids may befuel solids including, but not limited to, coke breeze, coke fines, coalfines and wood wastes. Alternatively, the particulate solids may benon-fuel particulate waste including, but not limited to, particulateradiation contaminates, metal wastes, toxic waste particulates and metaloxides. The adding step 120 may be performed in a batch operation, whereall of the particulate solids for a process batch are added at one time.Alternatively, the adding step 120 may be performed in a continuousprocess where the particulate solids are added in a continuous stream.

The particulate solids are blended with the composite waste product tocreate a mixture of the composite waste product and the particulatesolids 130. In the case of recycled carpet, the composite waste productgenerally includes, for example, a polypropylene binder element and anylon fiber element. The temperature of the mixture is increased tofluidize the binder element 140 through, for example, a combination ofheat generated by the mixing process and heat provided to the process byexternal devices 140. The fluid polypropylene binder element capturesthe fine particulate solids. Further, the nylon carpet fibers becometacky at the temperature at which the binder fluidizes, which causes thenylon carpet fiber to sinter to both the particulate solids and thefluid binder. In an embodiment, the process temperatures for fluidizingthe polypropylene binder without fluidizing the nylon fibers are in theexemplary range between 275 degrees F. and 450 degrees F. Thecombination of the fluid polypropylene binder and the nylon fiberresults in a mechanical capture of the particulate material in acombined polypropylene and nylon fiber polymer matrix.

The mixture is then formed into solid formed products, such as, forexample, briquettes or pellets, using heat and/or pressure 150. Afterthe forming process, the resulting solid formed product is structurallystable and does not retrogress into fine particles during storage andhandling. When particulate solids are fuel based, the solid formedproduct is bound reliably together and constitutes a high BTU fuel forindustrial, utility, and residential use which does not materiallypollute the air to a degree different from conventional fuels. In thecase of non-fuel particulate solids, such as industrial waste, the solidformed product is bound reliably together and constitutes a durablemeans of either recycling in a subsequent industrial process or longterm stable storage which does not materially pollute the air, soil, orground water.

Reference is now made to FIG. 2, which illustrates a block diagram of anexemplary process under the methods disclosed herein. The process 200combines recycled carpet 210 and particulate solids 220 into a mixtureby heating and blending or mixing as indicated in block 230.Additionally, other polymers 250 may be optionally added to achievespecific characteristics relating to mechanical properties, chemicalcomposition, or a combination thereof. After the heating and blending ormixing is completed, solid formed products are formed in block 240using, for example, conventional briquette or pellet forming technology.Additionally, one of ordinary skill in the art knows or will know thatthe mixture may be formed into solid products including extrusions,sheets or other homogeneous or non-homogeneous shapes, as needed.

Reference is now made to FIG. 3, which illustrates a block diagram of anexemplary process under the methods disclosed herein. The process 300utilizes recycled carpet 310, which is reduced in step 315. The reducingfunction includes, but is not limited to, shredding, grinding,pelletizing, and other techniques known by one of ordinary skill in theart. Additionally, as indicated in block 325, particulate solids 320 areprocessed to achieve a maximum particle size by grinding or crushing. Amixture of the reduced recycled carpet and the ground particulate solidsis produced by heating and blending or mixing, as indicated in block330. Additionally and optionally, recycled plastics may be added tomixture for supplemental fuel content and/or environmentally beneficialdisposal. After the heating and blending or mixing is completed, solidproducts are formed, as indicated in block 340, using conventionalforming technology including, but not limited to, the methods and formsdiscussed above.

Reference is briefly made to FIG. 4, which is a block diagramillustrating a non-limiting example of elements in a composite wasteproduct. An embodiment of the composite waste product 400 includes, butis not limited to, a polypropylene backing material 410, nylon carpetfibers 420 and calcium carbonate 430. The polypropylene backing material410 becomes fluid at a processing temperature allowing it to capture theparticulate solids. The nylon carpet fibers 420 become tacky, but notfluid at the processing temperature and, in the process of blending,serve to form a fiber matrix in the mixture. The calcium carbonateelement, when used in a sulfur containing fuel application and underpresent combustion methods may result in a reduction of sulfur dioxideemissions. This reduction diminishes or eliminates the utility ofpowdered limestone injection associated with conventional sulfur dioxideemission reduction methods. Additionally, remaining binding ingredientsinclude other polymers (not shown) as normal components of carpetbacking material.

Reference is now made to FIG. 5, which is a block diagram illustratingan exemplary process under the methods disclosed herein. An embodimentof the process 500 applies recycled baled carpet 510 to a bale breaker512 for subsequent processing by a shredder/grinder 514. Theshredder/grinder 514 is one of a number of reducing techniques known byone of ordinary skill in the art. The reduced carpet is then received byan accumulator 550. An accumulator 550 receives raw or intermediatelyprocessed materials from multiple sources. For example, in this case,the accumulator 550 receives reduced carpet and other materials, asdiscussed below, for subsequent processing.

As discussed above, recycled plastic 530 is optionally included in themixture to facilitate improved fuel content, mechanical properties, or acombination thereof, and to facilitate an environmentally beneficialmethod of disposal. To aid in processing, the recycled plastic 530 isprocessed through a shredder/grinder 532 and transferred to a mixer 540.In the case where specific chemical or mechanical properties aredesirable, additional virgin polymers 536 may be optionally added. Sincethe virgin polymers 536 are typically purchased in a form ready forprocessing, such as pellets, the virgin polymers 536 are depositeddirectly into the mixer 540.

In addition to the recycled plastic 530 and the virgin polymers 536,cellulose material 534, including but not limited to wood wastes, may beoptionally added to the mixture 540. The blending of cellulose material534 provides a partial fuel content from a renewable resource thusextending the life of available fossil fuels, such as the coal, PETcoke, or coke fines, with a clean burning alternative synthetic fuel.The synthetic solid fuels can be formed into various shapes and sizesfor use in devices including, but not limited to, stoker boilers,pulverized utility boilers, circulating fluidized bed (CFB) boilers,pressurized fluidized bed combustion (PFBC) boilers, coal gasification(IGCC) units, and wood and coal burning furnaces.

Coal or coke fines 520 are processed through a crusher or grinder 522 toreduce the particulate solid fuels to a maximum particle size. Thecrushed coal or coke fines are then transferred to the mixer 540. Thecontents of the mixer 540 including the processed coal or coke fines520, recycled plastic 530, cellulose 534 and virgin polymers 536 ismixed and transferred to the accumulator 550. The accumulator 550, whichincludes the combined contents of the mixer 540 and the recycled carpetfrom the shredder/grinder 514, conveys its contents to a pellet mill 560using a feeder 552.

The pellet mill 560 blends the combined contents and uses, for example,a combination of heat, pressure, and forming technology to form solidproducts, including but not limited to pellets, briquettes, extrusionsor sheets, of the mixture, which are then transferred to a cooler 562.After cooling, the solid products are structurally stable and do notretrogress into fine particles during storage and handling. The solidproducts are then transferred to storage 564 where they remain intactbecause the solid particulate materials are encapsulated to preventdegradation, leaching or contamination into the environment. The solidproducts also exhibit resistance to moisture because the moisture isdriven out by the process heat and then sealed out by the encapsulatingfunction of the binder element.

Reference is now made to FIG. 6, which illustrates a block diagram of anexemplary process under the methods disclosed herein. The process 600includes reducing waste carpet 610 including, but not limited to,shredding, grinding or pelletizing the waste carpet. Particulate solids,which may have a fuel content are added 620 and the particulate solidsare mixed with the waste carpet 630. The mixture is heated using, forexample, a combination of heat generated by the process plus anysupplemental heat necessary to fluidize the binder element of the wastecarpet 640. One of ordinary skill in the art knows or will know thatsupplemental heat may be provided by any number of methods including,but not limited to, electric resistive and inductive devices, combustioncausing devices, electromagnetic wave devices, and recaptured heat fromother processes. After the mixing is completed, the mixture is formedinto solid products by pressure, heat or extrusion 650, for example.

Reference is now made to FIG. 7, which is a block diagram illustratingcomponents of an exemplary production plant for practicing the methodsdisclosed herein. The plant 700 includes a composite waste reducer 710,which, for example, shreds, grinds, or pelletizes waste carpet. A solidparticulate delivery device 720 provides solid particulates to thereduced composite waste at, for example, a combining device 730. Thecombining device 730 combines the reduced composite waste product withparticulate solids to create a mixture. Additionally and possibly incombination with the combining device 730, heat generation/regulationequipment 740 provides sufficient supplemental heat to the mixture tofluidize one element of the composite waste product. The heated mixtureis then provided to a solid product forming device 750, configured toproduce solid formed products. The solid formed products include but arenot limited to pellets, briquettes, extrusions and sheets, among others.As discussed above, the solid formed products may be produced forsubsequent consumption wherein the solid particulates have a useful fuelcontent or other desirable recycle value. Alternatively, the solidformed product may provide a safe and effective method of storing andhandling useful or potentially harmful solid particulate materials. Theplant 700 also includes sufficient process control equipment 760 suchthat the production steps are integrated into a continuous process. Inthe alternative, the process control equipment 760 is configured, forexample, to perform production steps in independent stages.

The methods described herein do not require water, acids or any otherchemical or elemental component from the particulate solids to form thebond. As a result, virtually any particulate or blended materials can bereliably pelletized using methods described herein. Although wastecarpet is presented in an embodiment described herein, one of ordinaryskill in the art knows, or will know that any composite waste producthaving binder and fiber elements may be used. For example, polymerimpregnated cloth used in some industrial processes may also be asuitable composite waste product.

It should be emphasized that the above-described embodiments of thepresent disclosure, particularly, any illustrated embodiments, aremerely possible examples of implementations, merely set forth for aclear understanding of the principles of the disclosure. Many variationsand modifications may be made to the above-described embodiment(s) ofthe disclosure without departing substantially from the spirit andprinciples of the disclosure. All such modifications and variations areintended to be included herein within the scope of this disclosure andthe present disclosure and protected by the following claims.

1. A method for binding particulate solids, comprising the steps of:reducing a composite waste product that includes carpet, each componentof the composite waste product being in a solid state; combiningparticulate solids having fuel content with the composite waste productto create a consistent mixture; adding energy to the consistent mixtureto increase a process temperature, such that at least one component ofthe composite waste product changes from the solid state to a fluidstate; and forming the consistent mixture into a solid formed product.2. The method of claim 1, wherein the carpet comprises a polypropylenebinder element and a nylon fiber element.
 3. The method of claim 1,wherein the carpet comprises: a first element comprising a backingmaterial, wherein the backing material exhibits a first fluidizingtemperature; and a second element comprising a fiber material, whereinthe fiber material exhibits a second fluidizing temperature, and whereinthe first fluidizing temperature is lower than the second fluidizingtemperature.
 4. The method of claim 1, wherein the solid formed productis held together by the at least one component of the composite wasteproduct.
 5. The method of claim 4, wherein the at least one component ofthe composite waste product is a binder element of the carpet.
 6. Themethod of claim 1, wherein the particulate solids are selected from thegroup comprising: coke breeze, coke fines, and coal fines.
 7. The methodof claim 1, further comprising the step of adding a cellulose material,wherein the cellulose material comprises a renewable fuel resource forsupplementing the fuel content of the particulate solids.
 8. The methodof claim 1, wherein the solid formed product comprises a polymer fibermatrix, such that the particulate solids are reliably retained.
 9. Amethod for binding particulate solids, comprising the steps of: reducinga composite waste product that includes carpet, each component of thecomposite waste product being in a solid state; combining particulatesolids with the composite waste product to create a consistent mixture;adding energy to the consistent mixture to increase a processtemperature, such that at least one component of the composite wasteproduct changes from the solid state to a fluid state; forming theconsistent mixture into a solid formed product; and adding asupplemental polymer associated with the solid formed product, such thatthe supplemental polymer results in different solid formed productproperties.
 10. The method of claim 9, wherein the solid formed productexhibits moisture resistance.
 11. The method of claim 9, wherein theparticulate solids comprise non-fuel waste materials.
 12. The method ofclaim 9, wherein the particulate solids comprise materials with fuelcontent.
 13. The method of claim 9, wherein the solid formed product isheld together by the at least one component of the composite wasteproduct.
 14. The method of claim 13, wherein the at least one componentof the composite waste product is a binder element of the carpet.
 15. Adegradation resistant fiber matrix solid product, comprising: a carpetincluding a binder element and a fiber element, wherein the binderelement fluidizes at a first temperature, wherein the fiber elementfluidizes at a second temperature, and wherein the first temperature islower than the second temperature; and a particulate solid includingfuel particulates, wherein the binder element captures the particulatesolid when blended at a temperature in the range between the firsttemperature and the second temperature, and wherein the degradationresistant fiber matrix solid product is held together by the binderelement.
 16. The solid product of claim 15, wherein the fuelparticulates are selected from the group including: coke breeze, cokefines, and coal fines.
 17. The solid product of claim 15, wherein theparticulate solid further comprises non-fuel particulate materialselected from the group including: particulate radiation contaminants,metal particulates, toxic waste particulates, and metal oxideparticulates.
 18. A system for capturing particulate solids in adegradation resistant form, comprising: a reducing means for shreddingor pelletizing carpet; a supplying means for adding particulate solidsto the carpet; a mixing means for blending the carpet and theparticulate solids into a mixture; a heating means for elevating thetemperature of the mixture such that a binder element of the carpetachieves a fluid state and a fiber element of the carpet retains a solidstate; a forming means for converting the mixture into a solid, whereinthe solid comprises a polymer fiber matrix which captures theparticulate solids and is held together by the binder element; and asupplying means for adding a supplemental polymer, such that thesupplemental polymer results in different solid formed productproperties.
 19. The system of claim 18, wherein the particulate solidshave fuel content.
 20. The system of claim 18, wherein the binderelement comprises a backing material exhibiting a first fluidizingtemperature, wherein the fiber element comprises a fiber materialexhibiting a second fluidizing temperature, and wherein the firstfluidizing temperature is lower than the second fluidizing temperature.